In short
- Low albumin (below 36 g/L, or 3.6 g/dL) most often reflects inflammation or illness, liver disease, protein loss through the kidneys or gut, or poor nutrition. It is a reason to look for a cause, not a diagnosis.
- High albumin (above 48 g/L, or 4.8 g/dL) is almost always from dehydration or a concentrated sample, not disease.
- Albumin is a slow marker. It lasts about 20 days in the blood, so it moves over weeks, and inflammation and fluid balance move it more than diet does.
- Low albumin is not specific to the liver. Infection, inflammation, kidney loss and gut loss lower it too (BSG 2018).
- Low albumin makes total calcium look low. Ask about corrected or ionised calcium before worrying about calcium.
- See a doctor soon if low albumin comes with swollen legs, belly or eyelids, foamy urine or yellow skin.
Albumin sits quietly on most metabolic panels and rarely gets explained. This guide shows what a low or high albumin means, why it changes slowly and which markers tell you where to look next.
What does low albumin mean?
Low albumin means your blood holds less of its most common protein than usual. The liver makes albumin. It keeps fluid inside your blood vessels and carries hormones, vitamins, medicines and calcium. A low value tells you that production is down, loss is up, or the body is busy fighting inflammation.
It is a signal, not a disease. Albumin falls in many situations, including infection, inflammatory disease, kidney protein loss, poor absorption and gut protein loss. That is why a low albumin on its own does not prove a liver problem (BSG 2018).
What is the normal range for albumin?
For adults, Blood Lab 360 treats albumin of 36–48 g/L as within range. Below 36 g/L is low, and above 48 g/L is slightly high. For total protein, the range is 62–78 g/L. These bands come from the Nordic Reference Interval Project (NORIP).
| Marker and band | g/L | g/dL (US) | Reading |
|---|---|---|---|
| Albumin, low | below 36 | below 3.6 | Look for a cause with your doctor. |
| Albumin, within range | 36–48 | 3.6–4.8 | Within the reference range. |
| Albumin, slightly high | above 48 | above 4.8 | Usually dehydration; repeat well hydrated. |
| Total protein, low | below 62 | below 6.2 | Read with albumin; see a doctor if it persists. |
| Total protein, within range | 62–78 | 6.2–7.8 | Within the reference range. |
| Total protein, slightly high | above 78 | above 7.8 | Often dehydration; read in context. |
Source: NORIP, Reference intervals for common clinical chemistry components (Rustad et al., 2004), as used in the Blood Lab 360 knowledge base. Reference intervals differ between laboratories. To convert, g/dL = g/L ÷ 10.
What are the causes of low albumin?
The causes of low albumin fall into four groups: the liver makes too little, the body loses it, inflammation pushes it down, or protein intake is too low. MedlinePlus and StatPearls list these causes:
- Less production. Liver disease such as cirrhosis, hepatitis or advanced fatty liver disease. See fatty liver and FIB-4.
- Loss through the kidneys. Damaged kidney filters let albumin leak into the urine. With heavy loss (nephrotic syndrome), urine can look foamy.
- Loss through the gut or skin. Crohn's disease and other conditions that limit absorption, protein-losing gut disease and extensive burns.
- Inflammation and acute illness. Infection or long-lasting inflammation lowers albumin, even when the liver is healthy.
- Too little protein. Malnutrition or very low protein intake over a long time.
- Other. Thyroid disease. Albumin also falls naturally in pregnancy, and birth control pills can lower results.
In practice, a mildly low albumin in someone who has just been ill is common. It often returns to range once the illness has passed.
What does high albumin mean?
High albumin almost always means the sample is concentrated, not that you have too much protein. The usual reason is dehydration, for example after vomiting, diarrhoea or not drinking enough (MedlinePlus). Blood drawn with the tourniquet left on for a long time can also read a little high.
Steroids, insulin and some hormones can raise results too (MedlinePlus). There is no disease that raises albumin itself. Repeat the test well hydrated before reading anything into a slightly high value.
Why does albumin change so slowly?
Albumin changes slowly because it stays in the blood for about 20 days (StatPearls). A new cause needs weeks to show, and a fixed cause needs weeks to disappear. StatPearls notes that inflammation, nutrition, kidney or gut loss and fluid status all move it strongly.
This has two practical sides. A sudden drop within days is more likely from inflammation or fluid shifts than from diet. And eating more protein does not raise a low albumin quickly, unless poor intake was the cause. Albumin is also one of the inputs of the PhenoAge calculation, which we cover in biological age.
Which combinations with total protein, CRP, ALT and creatinine matter?
Albumin tells you where to look only when you read it with its neighbours. These are the patterns Blood Lab 360 checks:
- Low albumin with high hs-CRP (above 3 mg/L). Inflammation is the likely driver. Find its source first, then re-test after recovery. See hs-CRP and inflammation.
- Low albumin and low total protein. Overall protein is low: think of nutrition, loss or the liver.
- Low albumin with normal or high total protein. Total protein minus albumin gives the globulins, which are then high. This can fit chronic inflammation or infection, and less often a disorder of antibody production.
- Low albumin with raised ALT or bilirubin. Points towards the liver. See ALT, AST and GGT.
- Low albumin with raised creatinine or low eGFR. Points towards the kidneys. The key test is the urine albumin-to-creatinine ratio (microalbumin). KDIGO calls a ratio above 30 mg/mmol (300 mg/g) severely increased. See eGFR and creatinine.
- High albumin with high total protein. Both are concentrated, which fits dehydration.
- Low albumin with low calcium. Part of calcium rides on albumin, so total calcium reads falsely low. Corrected or ionised calcium gives the true picture.
See a doctor quickly if low albumin comes with swelling of the legs, ankles, belly or eyelids, foamy urine, yellow skin or eyes, or new breathlessness. The same applies when albumin keeps falling on repeat tests, or when it is low and you already have liver or kidney disease. One mildly low value after an infection is rarely an emergency. The pattern and the trend matter more. Our article on results outside the reference range explains why.
How Blood Lab 360 reads this
Blood Lab 360 reads albumin together with total protein, hs-CRP, ALT, bilirubin, creatinine, eGFR and calcium from the same report. If CRP is high, it tells you that inflammation may explain a low albumin. If calcium is low, it reminds you that albumin affects the total calcium number. Every range comes with its source.
Because albumin moves slowly, the suggested re-test is after about 24 weeks. Your doctor may want it sooner if you are unwell or have symptoms. The app explains your report; it does not diagnose.
Frequently asked questions
What is a normal albumin level?
For adults, Blood Lab 360 uses 36–48 g/L (3.6–4.8 g/dL) as within range, based on NORIP. Labs differ, so check the range on your report. Albumin is naturally lower in pregnancy.
What does it mean if albumin is high in a blood test?
Almost always dehydration or a concentrated sample. Drink normally and repeat the test. Some medicines, such as steroids and insulin, can also raise the result.
What are the symptoms of low albumin?
A mild drop usually causes no symptoms. With a marked drop, fluid leaks into tissues and causes swelling of the legs, belly or around the eyes. The underlying cause can add its own signs, such as foamy urine or jaundice.
Can eating more protein fix low albumin?
Only if too little protein was the cause, and even then slowly. Most low albumin comes from inflammation, liver or kidney disease or protein loss. Those causes need to be found and treated first.
What is the difference between albumin and total protein?
Total protein is all proteins in the blood: albumin plus globulins such as antibodies. Subtracting albumin from total protein gives the globulins, which help show whether inflammation or antibody production is involved.
Is low albumin serious?
It depends on how low it is and why. A mildly low value after an illness often settles on its own. A clearly low or falling value, or one with swelling, belongs with a doctor.
